Narrow Results

In the framework of the quasiparticle approach, the ground state mass of heavy pentaquarks have been investigated in diquark–diquark–antiquark picture and the higher states are investigated in the mass loaded flux tube model where two light diquarks are supposed to be linked by a flux tube to the heavy quark. The Regge trajectories for heavy pentaquarks have been studied. The Regge slope (α) of these particles have been obtained as ≈1 GeV² which indicates that the Regge trajectory follows the linearity conditions with universal value of α (~ 1 GeV²). The ground state mass of doubly charm and doubly bottom baryons like have also been investigated in quasiparticle approach. The results are found to be in reasonably good agreement with the experimental and other theoretical estimates.

The effect of quark mass on the Regge trajectory is analyzed. Modifications in the equations of Regge trajectories are shown for mesonic as well as baryonic systems. For mesonic systems, the Regge trajectories get modified, but still remain linear. Contrary to the mesonic case, the Regge trajectories for baryonic systems indicate nonlinearity. It is shown that in low mass and angular momentum region two hadrons with different quark compositions can have same mass and angular momentum.

We provide a brief summary of a method to calculate improvements to the Veneziano amplitude, creating sub-leading nonlinearities in the Regge trajectory of states. We formulate it as an extension of a computation by Makeenko and Olesen. We begin in a confining gauge theory coupled to matter, rewriting the meson scattering amplitude as a specific path integral over shapes and sizes of closed Wilson loops using the worldline formalism. We then prescribe how to further the computation at strong coupling by employing holography, which provides a prescription for the expectation value of these Wilson loops in strongly coupled regimes. The computation we desire then appears to subsume to a certain calculation in the effective field theory of a string worldsheet embedded in a certain broad class of allowed holographic backgrounds. A convenient interaction picture presents itself naturally in this context, allowing us to draw Feynman diagrams corresponding to the first few corrections due to weaker coupling regimes. The answer we find has qualitatively the same features as other endeavors with the same objective.

We have investigated the Regge trajectories of exotic hadrons by considering different possible pentaquark configurations with finite quark mass in the flux tube model. Significant deviation is observed in the linear behavior of the Regge trajectories for pentaquark systems in view of the universal value of the Regge slope parameter for hadrons. The modified Regge trajectories are also compared with the available experimental and lattice data. It is observed that the nonlinear Regge trajectories of such pentaquark systems can be well described by the relativistic corrections in view of the current quark masses and the high rotational speed of the quarks at the end of flux tube structure.

In this paper, we enumerated ground and excited state masses of singly heavy bottom-strange baryons using the hypercentral constituent quark model (hCQM). The screening potential is used with color-Coulomb potential, as the confining potential. We determine the possible $J^P$ values to recently observed excited states like, ${\mathrm{\Xi }}_b(6100)$, ${\mathrm{\Xi }}_b(6227)$, ${\mathrm{\Xi }}_b(6327)$, ${\mathrm{\Xi }}_b(6333)$ and four ${\mathrm{\Omega }}_b(6316,6330,6340,6350)$ states. The Regge trajectories are plotted in $(J,M^2)$ plane to assign the $J^P$ values and quantum numbers to recently observed states. Using the calculated spectroscopic data, properties such as magnetic moment, transition magnetic moment, radiative decay width, and strong decay width are also investigated for all singly heavy bottom-strange baryonic system.

The spectroscopy of light and strange baryons had been an important aspect with still unknown resonances and intrinsic baryonic properties. This paper focuses on the $\mathrm{\Delta }$ baryons treating $u$ and $d$ quarks with different constituent masses. The theoretical framework for calculating the resonance masses is hypercentral Constituent Quark Model (hCQM) with confining potential of the linear form. To account for the spin–orbit splitting in the correct order, first- and second-order corrections of the order $1∕m$ and $1∕m^2$ have been incorporated to the potential and spin-dependent term, respectively. The results obtained have been compared with many varied approaches as well as experimental available states. In addition to mass spectra, Regge trajectories for (n, $M^2$) and ($J$, $M^2$) have been plotted. The magnetic moment as well as transition magnetic moment have been calculated using effective quark mass. The radiative decay width has been studied for ${\mathrm{\Delta }}^{+}$ and ${\mathrm{\Delta }}^0$ channels.

In this paper, we study the properties of triply charm and triply bottom baryon. The mass spectra of these baryons are calculated in nonrelativistic constituent quark model with Coulomb plus screened potential. Several states $S$, $P$, $D$ and $F$ of the ${\mathrm{\Omega }}_{ccc}$ and ${\mathrm{\Omega }}_{bbb}$ baryons with quantum number $J^P={\frac{1}{2}}^{\pm }$, ${\frac{3}{2}}^{\pm }$, ${\frac{5}{2}}^{\pm }$, ${\frac{7}{2}}^{\pm }$ are determined. Regge trajectories are also plotted to determine the quantum number of baryons. Moreover, the magnetic moments are calculated for $J^P={\frac{3}{2}}^{+}$.

The hypercentral Constituent Quark Model (hCQM) has been employed to obtain the resonance masses of hadrons ranging from light, strange to heavy sector. This work is dedicated towards incorporating the higher order correction in the mass so as to improve the spin-order hierarchy. The potential is Coulomb-like part and linear term as confinement part along with the spin–spin interaction terms. In this paper, the light, strange baryon masses have been revisited with correction term with $\frac{1}{m}$ and $\frac{1}{m^2}$ and compared with earlier results as well as various other approaches. The slope and intercepts have been recalculated for obtained masses which are expected to aid in experimental findings. The recent results are found to be in good accordance with the experimental range as well as theoretical models.

In this study, singly charm baryons ${\mathrm{\Lambda }}_c$, ${\mathrm{\Sigma }}_c$, ${\mathrm{\Xi }}_c$ and ${\mathrm{\Omega }}_c$ have been studied. The known hypercentral Constituent Quark Model (hCQM) has been subjected to an addition of second-order correction term to the mass in spin-dependent term. This has allowed to observe the expected spin-splitting in the correct order and modify the previous findings to a new level. All the other properties have been obtained ranging from magnetic moment to strong decay width along with the linearly observed Regge trajectories.

This work is devoted to the study of charmonium S-states by solving the Schrödinger equation with Cornell plus spin–spin interaction term via the artificial neural network (ANN) approach. From the solutions provided by ANN approach, we propose possible assignments for some of the recently discovered charmonium-like resonances. For simplicity purpose, we restricted the study to the ground and radially excited S-states of charmonium. The charmonium wave function is represented by the feed forward ANN and its inputs are assimilated to coordinate values. We calculated the masses, hyperfine splittings, spin-averaged mass spectrum and Regge trajectories of pseudoscalar and vector charmonium states. Overall, our results are in good accordance with the available experimental data and past studies of the mass spectrum of $J^{\mathrm{\text{PC}}}=1^{--}$ and $J^{\mathrm{\text{PC}}}=0^{-+}$ charmonium states. Further, we propose a possible assignment for some of the recently discovered charmonium-like mesons. We concluded that ${\eta }_c(3S)$, ${\eta }_c(4S)$, $\psi (4S)$, ${\eta }_c(5S)$ and $\psi (6S)$ are, respectively, good candidates of $X(3940)$, $X(4160)$, $Y(4260)$, $\psi (4415)$ and $Y(4660)$ charmonium-like resonances.

We show that a dynamical AdS/QCD model is able to reproduce the linear Regge trajectories for the light-flavor sector of mesons with high spin and also for the scalar and pseudo-scalar ones. In addition the model has confinement by the Wilson loop criteria and a mass gap. We also calculate the decay amplitude of scalars into two pion with a good agreement with the available experimental data.

The meson mass spectra are obtained by solving exactly the two-body Dirac equation for the linear plus Coulomb potentials with complex spin-angular structure. In such a solvable model, the orbital excited heavy meson states as well as the orbital light meson states agree well with available experimental data. It turns out that the quark-antiquark interaction potential may be more intricate than those predicted so far.

Implications of the renormalization group for Regge trajectories are discussed.